Several devices are known in the prior art which are used for sewing pieces of buckram material to the tops of drapery panels. While the prior art has recognized that space utilization is a problem, most previous attempts reached the conclusion the problem is best solved if the sewing machine was moved relative to the work table or if the surface supporting the drapery material were moved relative to the sewing machine.
The prior art devices, however, have not truly overcome space problems since the support tables used with prior art devices of which applicants are aware, are comprised of a large table capable of suporting the entire length and width of drapery panels. It can be appreciated that because of the length and width of certain drapery panels, work tables for supporting such panels must be relatively large in size.
Another problem that has not been recognized in the prior art concerns the proper alignment of the top of the drapery panel with the strip of buckram that is to be joined therewith so that the resulting seam runs along a straight, square edge. This becomes important during the subsequent pleating of the top edge since the top of each finished panel is determined by the subsequent folding of the top edge of the drapery panel to which the buckram has been applied. If the buckram has not been applied correctly, the top edge of the finished panel will not be straight and undesirable folds may well be created in any attempt to straighten out the top edge.
Another problem experienced with prior art apparatus has been the secureness of the clamped relationship between the buckram being applied and the top edge of the panel. Two prior art devices known to the applicant are set forth in Kenney, U.S. Pat. No. 3,874,311 and McClintock, U.S. Pat. No. 3,400,674.
In both the above patents the supply of buckram is supported by the sewing machine. As the sewing machine and drapery panel are moved, one relative to the other, the supply of buckram is placed in contact with the drapery panel just prior to the part where the buckram is sewn in place by the sewing machine. The only clamping that occurs between the strip of buckram and the top edge of the drapery panel is created by the presser foot of the sewing machine. In the Kenney apparatus, the sewing machine moves relative to the work while in the McClintock apparatus the work table moves relative to a fixed sewing machine. In either case, however, because the buckram is being applied to a drapery panel which is moved relative to the sewing machine a wave is, in effect, formed in the panel by the sewing machine presser foot. This creates folds or creases along the top edge of the panel ahead of the presser foot along the unclamped top edge of the panel. Further, the friction caused by the presser foot coming into contact with the drapery panel stretches the drapery material. Thus, when the top of the panel is folded, the top edge will be wider than the body portion of the panel due to the stretching. This, of course, makes the formation of square corners very difficult. In most instances, these folds or creases are immediately sewn in place by means of the sewing machine. Such folds and creases are, of course, undesirable since these appear in amplified form when pleats are subsequently formed along the top edge of the drapery panel.
Another problem not recognized in the prior art concerns the removal of drapery panels from the support or work table subsequent to the sewing process. Drapery panels are, of necessity, usually quite large and removal has, by and large, been a task for the operator. This adds another operator function to the process and increases the time involved. The present invention provides a doffing system which is automatically activated at the proper time so that during the doffing process the operator can be preparing the next panel. Thus, the number of operator tasks have been reduced and the time for the process has also been lessened.